Helicopter



June 28, 1949f T. s, KERANEN 2,474,362

HELICOPTER.

Filed Sept. 14', 1944' 5 Sheets-sheaf 1 Inventor THEODORE 5. KERANEN,

T. S. KERANEN HELICOPTER June 28, 1949.

Filed Sept. 14, 1944 5 Sheets-Sheet 3 THEODORE 5. KERANEN,

" Inventor June 1949. T. s. KERANEN 2,474,362 7 HHHHHHHH ER 'WWWZZM June 28, 1949. T. s. KERANEN I HELICOPTER Filed Sept. 14, 1944 5 Sheets-Sheet 5 Inventor THEODORE 5. KERANEN,

Patented June 28, 194-9 NIKTED s rATEs HELICOPTER ITheodore S; l'Keranen,'"DetroitjMich.

Application September 1431844; SerialeNoi$t54;0.7 2

1 Claim.

1 This invention relatesto arhelicopter, and more particularly 'to rant improved: :method for con- :trollinga. a. helicopter.

1 The primary-object of this invention isthe provision of. anvimprovedcontrol means for helicopters havingrotors; wherebylathe [pitch of thexrotor blades is varied during each rotation .thereofin such :'manner' :that the;.;advancing. blades .have

a: different pitch :from'i the retreating blades.

.An.radditionalnobjectrisithe provision of such means for vanyingrthe .angle of pitch of the advancingzand retreating. rotor blades of a helicopter .rhavingtwo -.counter-:rotating :rotors.

Still another. .object' is the provision of. a helipcopter rwhich may be" wholly controlled-by the angle of pitch of the blades ofthe rotors, without theunecessity :forvarying the axes of rotation of the rotors 'angularly.

=Ats'till=further object is the provision of control meansiwhereby thei difference-between the pitch aofthe advancing and retreating rotor blades may he varied as desired.

A still further object is-the provision, in a hellcopter having counter-rotating rotors, 'of'means for simultaneously varying the pitch of the' advancing and retreating blades of both rotors in a predetermined ratio.

-' Still another object is -the-provision,' in a helicopter-having-counter-rotatingrotors, of .means p .cthncughoutrthe severataziews:otzthe' drawings.

' for varying'the 'ratio' of 'the pitch of the blades of one rotor with respecttoihe pitch of the blades of the other.

Still another important. object -is;the..provision :of. a helicopter .wherein the direction 7 offlight,

either straight, upand down vertically, forwardly,"

or rearwardly,..orl. toi thetrightor. left, may be .varied. solely .by. ivariation. of the pitch .ofthe rotor blades.

.Other objectsreside in. the combination of elements, arrangement of. parts and features of con- ..struction; al1,. as wil1 be more .fully pointed? out ,hereinafter and..disclosed:in the accompanying drawings, whereinz-there -.is--shown a preferred embodiment of this. inventive concept.

..=In:the drawings: s Figure 1 ':is. a side aelevationalview; partially in section, of a- 1 helicopter embodying: features of this inventive concept, certaina-partslthereof being indicated.- by: dottedlines.

'-Figure' 2' is 2.. top; plan viewaof the a-helicopter sshowndnnFigurei 1.

z-Eigure. 3:-.is:.an .enlargedas'ectional :view taken rthroughthe coenterdinesoiithe; hub iof: .the rotors ofstheehelicopter.

332 Figure 4 is a sectional view-taken substantially valongr-thevline Ila-4110f FigureS.

Eig ure. Eris a sectional-view .taken substantially aalong..theglineHE-TI-E of Figure.- 3; viewed in the 5 direction [indicated by lthe-.-arrows.

r-Eignre dds aesectionalfview taken-substantially along. the line 6-e-6 .01 Eig-ureB as viewed in the direction indicated -]oy. the; arrows. I

'efigure '7"is anlenlargediperspective view of cer- 10..-tain:lconstructionalaelements.

.---Fig;ure-: 8 is-. avschematic; {eleyational viewof a y portion: of thecontrolcsystem zfor the helicopter. 1' Figure, ens. a-='sectionalwiew taken substantially ...alongithel-linetll-ll 101?: Fi ure 8; as viewed in the lat direction Radicatei-Jowthe,arrows.

Eig-urez lmis. an enlarged sectional view taken 5' substantially; along .the. line-ll ll.-.l 0 of Figure 6.

pEi-g-urei, ill-As". amenlal edi sectional view taken substantially/among the-.li-ne- I-l---l of-F-igure 6 and :viemvedi in the-direction indicated loy the ar- ';r0Ws;.a/nd

ir'E ureglz ist avsectional view; talcenv along the :line .-I'2 l 2: oFEigureBsms :viewed in the direction indicated joy the;.-arrows. 2 Eigureuwzis aafragnientarywelevational view of a constructionahdetail; c.ertain:-concealed:parts ithenelof'beingrindicatedin:dottedilines andbther 5 lpartsrbeihgiomitted.

f hikei-z-reierencennumeralsxreier i-to. like" parts 1fiaivingrmeierencennowojto the: drawings, and :more; particnlanlygto Fignres laand' 2",?thereis genenal lylziindicatedi atc=2lh aIizhEIiCGPtBBE'DOGy having a cockpit 22 Irandanzopenatorsrposition 22'therein. ;rfnontiandaeamlandingawheelsaz 3-..and :24; respecitiviely, :and eontainingaaimotor i251provided with aazdrivehshaftiiifi. rl'nrivezish aitl 2e extends to a E transmission generallyrindicated. atz'lgsto be more fullmdescribedrheneinatter. .xAnc'ontrol shaft gen- 40- ,zerallyzimdioatechat :2 8;;lal'so ztoirbe Ldescribed more 7 tf-nlly hereinafterxeXtendstthnongh. asuitable bearjng:29rirr-the1rfa1selage, toanrotor hub generally ..gindicated;at dmmompnisedaof. arzcasing including .ammipen secticm B l a :iowenzseotionti 132, and V a rtopi33. :vSections 3 Land. 132 are each provided with .trotor. blades-$4 amctz35r; andfi &and 31-, respectively, anckaections .3 t andazsa areoa'daptedatoube. driven -atom-matationtzim nppositegdirections;.:in a manner 1. .120 rbe more chilly pointed out Lherein'after. Auxiliary control means- .lcomprisedsphvertical and 1'; horizontal rstaloilizerstfiBrandicfillxsrespectively, a X rudder-E Mwandjelevatorst 4.1 :xmam be provided if :I-riesirrcl;- although lthenhelicopter: r-sis operable as "mill-bepointed-mm hereinaitenmithout such aux- .5 illary controls. "1'Bositioned*iwithinrithe cockpit 2I is a control stick 42 connected through controls generally indicated at A3 and in a manner to be described hereinafter with means for varying the pitch of the rotor blades.

Referring back now to transmission 21, as best shown in Figures 3 and 6, drive shaft 26 has a bevel gear splined thereto and held in place between a collar 41 on shaft 26 and a Washer 48 on the opposite side of the gear, as by a holding nut 63. Gear is adapted to engage a bevel gear at to which is splined a drive shaft 5| provided with a collar '52 and held in place as by a nut 53. Drive shaft 5! extends upwardly from the transmission through rotor hub 30, andis fixedly secured at its upper extremity 54 in a flange 55 comprising an integral part of upper portion 3! of hub 30, being secured thereto as by splines and a lock nut 58, in such manner that rotation of drive shaft 5! through drive shaft 2e and gears and 50 occasions rotation of the upper portion 3I of the hub 30.

Gear d6 also drivesa second bevel gear 51 splined to a sleeve 58 coaxial with and surrounding drive shaft 5|, and is secured on sleeve 58,

as by a lock nut 59 and washer E0. Sleeve 58 also re,

extends upwardly out of the fuselage, and comprises the exterior portion of the driving column previously referred to as being generally indicated at 20. The upper extremity of sleeve 58 is suitably secured in an aperture in the lower portion of lower member 32 of rotor hub 30 and secured thereto, as by means of a washer 6| and lock nut 62, the arrangement being such that portion 32 driven by gear 51 thus rotates oppositely with respect to the portion 3| of hub 30 Y driven by gear 50. Means are provided for facilitating the counter-rotation of the portions 3| and 32 of hub 30, such means taking the form of an inwardly turned flange 63 about the upper surface of portion 32 to which is secured onehalf 65 of a ball race provided with bearings 65, the other half 63 of the ball race being secured to a flange 67 peripherally positioned about the lower surface of hub portion 3|. The space between the two portions is sealed against the escape of lubricant, as by a gasket 69.

The sleeve 53 is mounted for free rotation on needle bearings I0 and II positioned between sleeve '53 and an interiorly positioned sleeve '15, surrounding a second sleeve I6, within which latter drive shaft 5| is positioned for free rotation. Sleeves I5 and I6 serve to control the pitch of the rotor blades, in a manner now to be described.

Secured to the lower end of sleeve I6 is a collar ITI held in position against rotation, as by a spline l0, and secured on the sleeve by a lock nut I9. Collar 11 is, as best shown in Figure 11, provided with an extending arm 90 terminating in a ball 8I engaged by a socket 82 from which extends a control rod 83 comprising a portion of the control means heretofore generally designated by the reference character 43. The opposite end of control rod 83 terminates, as best shown in Figure 9, in a socket 84 engaging a ball 85 threadedly secured to control rod 42. From the foregoing it will now be seen that movement of the control rod 42, in a fore and aft direction, will effect rotation of control sleeve I6 through the connections above described, for a purpose to be more fully pointed out hereinafter.

Secured about the lower extremity of sleeve I5 is a collar having a peripheral groove 9| therein, within which are adapted to engage shoes 92 pivotally mounted; as on pivots 93, in the bifurcations 04 (see Fig. 10) of a lever 95.

Lever 95 is pivoted, as on a pivot pin 96, the extremities of which are secured in any desired manner to the walls of the transmission (not shown), and provided at its extremity with a ball 91. Ball 91 engages, as best shown in Figure 6, in a socket 90 formed at one end of a link 99, the other end of which is provided with a socket I00 adapted to engage a ball IIII secured to the end of a bell crank lever I02 pivotally mounted, as on a pivot I03, secured to the walls of the transmission housing. The other end of bell crank lever I02 has pivotally secured thereto, as on a pivot I04, a control rod I05. The opposite end of control rod I05 is pivotally secured, as best shown in Figure 9, on a pivot I06 mounted on one end of a bell crank lever I0I which in turn is pivoted on a vertical pivot I08 adjacent control lever 42. The opposite end of bell crank lever I01 has secured thereto, as on a pivot I09, a link I ll) terminating in a socket I I I surrounding a ball l I2 secured to control lever 42.

From the foregoing it will now be seen that movement of the control rod 42 to the right or left with respect to the axis of the helicopter will occasion, through the linkage above described, a movement of the sleeve I5 upwardly or downwardly, for a purpose to be described hereinafter. Sleeve I5 is secured to sleeve I6 adjacent its upper extremity, as by means of screws I I3 engaging suitable threaded apertures in sleeve It and passing through transverse slots II II in sleeve I5, the arrangement being such that sleeve I5 is free to rotate, when actuated by control lever 83 in the manner previously described, with respect to sleeve I6, but when sleeve I6 is moved upwardly or downwardly in the manner just above described, sleeve I5 is moved therewith.

The upper end of sleeve I5 is bifurcated to form a pair of tongues H5 and 6, respectively. Sleeve 76 is also bifurcated at its upper extremity to form a pair of tongues II! and H8, which tongues extend upwardly to a point adjacent the extremities of tongues I I5 and H6, but at substantially right angled relation thereto (see Fi ure 3).

Surrounding drive shaft 5I, at a point adjacent the tongues at the other extremities of sleeves I5 and I6, is a circular collar generally indicated at I20 provided with an interiorly disposed vertical bore I2I tapered outwardly adjacent its extremities and convex in cross section, as best shown in Figures 3 and 12. Oppositely disposed screws I22 and I23 extend outwardly through helical slots I24 and I25, respectively, formed in the collar I20, one of which is best shown in Figure 7, and have their inner ends engaged in suitable threaded apertures in tongues II I and IIO to hold the collar I20 in movable related assembly with the sleeve I6. As best shown in Figure 3, screws I26 and I 2! pass through suitable apertures I28 and I29 in spheres I30 and I3I, respectively, and have their inner ends secured in suitable threaded apertures in sleeve I5. Spheres I30 and I3I are adapted to seat respectively in grooves I 32 and I33 of substantiall circular cross section, and of helical configuration, provided with slots I 34 and I35, respectively, through which the heads of screws l26 and I21 extend.

From the foregoing it will now be seen that movement of sleeves I5 and I6, either vertically or rotatably with respect to each other, will eifect, due to the engagement of the screws and spheres above mentioned, with their associated helical grooves and slots, a tilting movement of collar I2I with .two bearings comprised respectively of inner rings lll and I4! a plurality oflballebeara -,-ings M2 and I53 and outerjrings l l l andrI-45.

Outer ring I45 is provided-as bestshown. in

. Figure 3,-with a pair of oppositely disposed balls I46 and I l! adapted to engage respectively in sockets I45 and --I-49-formed at the extremities oflinks I55 and NH. Similarly, outer ring :I44wis provided-with oppositely disposed ballsol 52' and I I53, disposed in right angnlarrrelationswith respect to the balls I41 and I45, adapted to engage the sockets of corresponding links I54 and I55:

(see Fig. 7).

As best shown in Figure 4, link I54 terminates in a cylindrical portion I56 having a bore I51 therethrough adapted to engage the cylindrical end I58 of an arcuate member I59, the opposite end of which is secured, as by a spline I60 (see Fig. 3), to the hub I5I of rotor blade 35, and secured against longitudinal displacement thereon, as by a lock nut I62 engaging a threaded extremity of the blade. Hub I6I of blade 35 is journaled for rotation in a pair of ball races I63 and I64 and held in position in main hub 3!, as by a lock nut I65.

The opposite link I55 terminates in a ball I66 adapted to be engaged by a socket I61 comprising the extremity of a similar arcuate arm I68 secured, as by a splin I69, to the hub I10 of rotor blade 34, and secured thereon, as by a lock nut I1I. Blade 34 is likewise journaled in a pair of ball races I12 and I13 mounted in casing 3I, and secured in position, as by a lock nut I15.

From the foregoing it will now be seen that tilting of collar I in the manner previously described effects, through arcuate arms I59 and 165, a corresponding change in pitch in rotor blades 34 and 35.

Referring back now to links I50 and I5I, it will be seen by consideration of Figure '7 that link I5I terminates in a cylindrical portion I18 within which is secured, as by a. nut I19, a cylindrical portion I80 of an arcuate arm IBI similar in configuration to arm I59. The end of link I56 terminates in a ball I82 adapted to be engaged in a socket I83 comprising the end of an arcuate arm I84 similar in configuration to arm I68, the end of which is secured to rotor blade 35 in a manner similar to that above described in connection with arm I68. Correspondingly, arm I8I is secured to rotor blade 31.

From the foregoing the operation of the device should now be readily understandable. It will be seen that tilting of collar I20 in the manner previously described to the position as shown, for example, in Figure 3, assuming that the direction of forward flight of the plane is toward the right, as viewed in the drawing, and that the upper rotor is rotating in a counter-clockwise direction in a plane at right angles to the plane of the drawing, and the lower rotor in a clockwise direction in a similar plane, it will now be seen that the blade 35 is in a low pitch position or angle, while the blade 34 is in a high pitch position, the position varying from high to low throughout a complete revolution of the rotor, effected by the coaction of inner and outer rings I40 and I44. Correspondingly, it will be seen that in the position as shown in the drawing, the blades 31 and 36 are now in an intermediate position, and that as the lower rotor rotates and xthese-iblad'es assumezresp'ectivelyathezpositionsrof zablades :35f-and 34:;sblade 3 willz'assnme, azlowpitch ..:.during chalf-pcof its: cycle: ,of.

.=.pitch .duringZ-the :othenhalf-I thereof Accordingly, dsin'ce: greater;:tractivazforce .=,is':.:'eXert'ed. ,by;.: :b'.oth

=rot'ationizand a:,high

rotors during theihalveszofi their; cycles; *fofrotation whenithey. are moving towards .the rearthan duringithe: halves; of :thcse' cycles'rwhenithey; are movingitowardsithefironti forwardmotion ofzthe plane will result. I

- Obviously, rearward/motion of the helicopter will be effected by reversing the angle of tilt of housing I20. -When it is desired-to lift the plane .vertically, housing I20 is shifted-to'horizontal position equalizing the pitchmof theablades throughout their full cycles of rotation. It will also be obvious that when it is desired to tilt the plane to the right or left, the collar I20 may be moved upwardly or downwardly in a vertical plane by means of the sleeve 16 and its associated controlling mechanism, and then as the housing moves upwardly, for example, the pitch of the blades of the upper rotor will be decreased, through the connection aflorded by the links I54 and I55 and the arms I59 and I68, and the pitch of the blades of the lower rotor increased, through the action of links I56 and I5I on arms IBI and I84, vertical movement of the links by the collar serving to rotate the arms and their associated blades, and vice versa, whereby turning action is effected in the direction of rotation of the rotor exerting the greatest pressure against the air.

If, for any reason, such as power failure or other causes, it becomes necessary to land the plane absolutely vertically, the clutch mechanism of the motor is thrown out and the vertical fall of the helicopter effects reverse rotation of the blades of the rotors, which then act in a known manner to preclude too swift a fall of the plane.

This invention has been described in relation to a helicopter having upper and lower rotors of two blades each, and it will be readily understood that any desired number of blades may be utilized by the addition of appropriate parts to control the same.

From the foregoing it will now be seen that there is herein provided a helicopter which may be controlled as to vertical lift, forward and rearward motion, as well as directional motion, upwardly or downwardly or to the right or to the left, solely by variation in the pitch of the rotor blades, without the necessity of tilting the plane of rotation of the rotors with respect to the aircraft. It will also be seen that there is herein provided a device accomplishing all the objects of this invention, and many others, including advantages of great practical utility and commercial importance.

As many embodiments may be made of this inventive concept, and as many modifications may be made in the embodiment hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense.

I claim:

In a helicopter in combination, an upper rotor provided with rotatively mounted blades, a lower rotor provided with rotatively mounted blades, means including a drive shaft and a drive sleeve for rotating said rotors in opposite directions, a second sleeve coaxial with said first-mentioned sleeve and said drive shaft, a collar pivotally secured to said second sleeve, means pivotally connecting the hubs of said blades with said collar, means for tilting said collar to change the pitch of said blades during a cycle of rotation, and means for varying the relative position of said collar to vary the pitch on the blades of one of said rotors with respect to the blades of the other of said rotors, said last-mentioned means including a third sleeve coaxial with said second sleeve and secured to said housing, and means for moving said last-mentioned sleeve in a vertical direction with respect to the horizontal plane of rotation of said rotor blades.

THEODORE S. KERANEN.

REFERENCES CITED The following references are of record in the file of this patent:

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